U.S. patent number 5,304,326 [Application Number 07/995,916] was granted by the patent office on 1994-04-19 for thermoplastic elastomer compounds.
This patent grant is currently assigned to Hyperion Catalysis International, Inc.. Invention is credited to Kohei Goto, Takumi Miyachi, Motokazu Takeuchi.
United States Patent |
5,304,326 |
Goto , et al. |
April 19, 1994 |
Thermoplastic elastomer compounds
Abstract
A crosslinked thermoplastic elastomer composition obtained by
mixing 100 weight parts of at least one type of thermoplastic
elastomer, 0-200 weight parts of a rubber-like polymer, and 1-50
weight parts of ultra fine carbon fibrils whose diameter is 3.5-70
nm and whose aspect ratio is greater than 5 against 100 weight
parts of the combined mixture of the aforementioned elastomer and
rubber like polymer.
Inventors: |
Goto; Kohei (Tokyo,
JP), Takeuchi; Motokazu (Tokyo, JP),
Miyachi; Takumi (Tokyo, JP) |
Assignee: |
Hyperion Catalysis International,
Inc. (Cambridge, MA)
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Family
ID: |
14240867 |
Appl.
No.: |
07/995,916 |
Filed: |
December 17, 1992 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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511780 |
Apr 18, 1990 |
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Foreign Application Priority Data
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Apr 19, 1989 [JP] |
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1-99195 |
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Current U.S.
Class: |
252/511; 524/495;
524/496 |
Current CPC
Class: |
C08K
7/06 (20130101); C08L 21/00 (20130101); H01B
1/24 (20130101); H01B 3/30 (20130101); H05K
9/0098 (20130101); H05K 9/0083 (20130101); C08L
21/00 (20130101); C08K 2201/016 (20130101); C08L
2666/02 (20130101) |
Current International
Class: |
C08L
21/00 (20060101); C08K 7/06 (20060101); C08K
7/00 (20060101); H01B 1/24 (20060101); H01B
3/30 (20060101); H05K 9/00 (20060101); H01B
001/04 (); H01C 001/04 () |
Field of
Search: |
;252/511
;524/495,496 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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0198558 |
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Oct 1986 |
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EP |
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56-088442 |
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Jul 1981 |
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JP |
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59-152299 |
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Aug 1984 |
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JP |
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61-132600 |
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Nov 1984 |
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JP |
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63-280786 |
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May 1987 |
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JP |
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63-286443 |
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May 1987 |
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JP |
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63-286468 |
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May 1987 |
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JP |
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62-505198 |
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Jun 1988 |
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JP |
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87/01317 |
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Oct 1987 |
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WO |
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729211 |
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Apr 1980 |
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SU |
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925969 |
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May 1982 |
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SU |
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1469930 |
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Apr 1987 |
|
GB |
|
Other References
"Beacon Gas-Conversion Process yelds Useful Carbon Materials"
(R&D-Jan. 1987). .
Endo, "Grow Carbon Fibers in the Vapor Phase", Chemtech, pp.
568-576 (Sep. 1988). .
Tibbetts et al., SAMPE Journal (Sep./Oct. 1986), pp.
30-35..
|
Primary Examiner: Bell; Mark L.
Assistant Examiner: Jones; Deborah
Attorney, Agent or Firm: Curtis, Morris & Safford
Parent Case Text
This application is a continuation of application Ser. No.
07/511,780, filed Apr. 18, 1990, now abandoned.
Claims
We claim:
1. A crosslinked thermoplastic elastomer composition
comprising:
(a) 100 weight parts of at least one thermoplastic elastomer;
(b) Greater than 0 and less than 200 weight parts of a
non-thermoplastic elastomer rubber per 100 weight parts of the
thermoplastic elastomer, and
(c) 1-50 weight parts of ultra-fine carbon fibrils whose diameter
is 3.5-70 nm and whose aspect ratio is greater than 5 per 100
weight parts of the combined mixture of said thermoplastic
elastomer and said rubber.
2. The composition of claim 1 wherein the diameter of said fibrils
is 7-25 nm.
3. The composition of claim 1 wherein said thermoplastic elastomer
is selected from the group consisting of 1,2-polybutadiene,
styrene, butadiene-styrene block copolymer or the hydrogenated form
thereof, and styrene-isoprene-styrene block copolymer or the
hydrogenated form thereof.
4. The composition of claim 2 wherein the 1,2-vinyl content of said
1,2-polybutadiene is at least 30%.
5. The composition of claim 2 wherein the molecular weight of said
1,2-polybutadiene is at least 1,000.
6. The composition of claim 2 wherein the degree of crystallization
of said 1,2-polybutadiene is 10-70%.
7. The composition of claim 1 wherein said rubber comprises natural
rubber, polyisoprene, cis-1,4-polybutadiene, styrene-butadiene
copolymer rubber ethylene-propylene di-functional monomer rubber,
chloroprene rubber, butyl rubber, halogenated butyl rubber,
acrylonitrile-butadiene copolymer rubber, and acrylic rubber.
8. The composition of claim 1 wherein the amount of said carbon
fibrils is 2-30 parts per 100 weight parts of the combined mixture
of said thermoplastic elastomer and said rubber.
9. The composition of claim 1 wherein the amount of said carbon
fibrils is 3-20 parts per 100 weight parts of the combined mixture
of said thermoplastic elastomer and said rubber.
10. The composition of claim 1 wherein said carbon fibrils comprise
essentially cylindrical discrete carbon fibrils having an outer
region of multiple essentially continuous layers of ordered carbon
atoms and a distinct inner core region, each of the layers and core
disposed substantially about the cylindrical axis of the
fibril.
11. The composition of claim 10 wherein said fibrils are
substantially free of a film of pyrolytically deposited thermal
carbon.
12. The composition of claim 5, wherein the molecular weight of
said 1,2-polybutadiene is at least 10,000.
Description
BACKGROUND OF THE INVENTION
The present invention relates to a polymer compound which contains
a thermoplastic elastomer, or more specifically it relates to a
thermoplastic elastomer compound with superior reinforcing
characteristics as well as with either electrical conductivity or
electrical insulating characteristics, produced by compounding
ultra-fine carbon fibrils.
Recently, there is an increasing demand for electrically conductive
or electrically insulating polymer materials used in electronic
parts or semiconductive layers of power cables for the purpose of
preventing static generation or interferences from external
electromagnetic waves.
Conventionally, the method of filling electrically conductive
carbon-black in a matrix polymer has been used as a way to add
electrically conductive characteristics to a rubber. Although it
achieves the desired electrical conductivity, the method fails to
reinforce the strength of the material. On the other hand, the
system of adding reinforcing type carbon-black results in the
desired reinforcing effect when as much as 30-100 phr is filled
(wt. parts against 100 wt. parts of rubber). However, the system is
absolutely ineffective in increasing electrical conductivity.
Incidentally, both reinforcing and electrically conductive effects
can be obtained by compounding chopped carbon fibers which possess
both of these effects. However, such fiber is not necessarily a
satisfactory reinforcing material because of its poor molding
characteristics, the poor surface appearance of the molded
products, and anisotropic nature. Moreover, its reinforcing effects
depend on the processing conditions since its short fibers break
during the processing.
Recently, ultra-fine carbon fibrils became available, and the
possibility of compounding such carbon fibrils in a resin or
rubber-like polymer has been discussed. However it has been
difficult to obtain a material with well balanced properties
including suitable hardness and superior elasticity.
The present invention intends to offer a thermoplastic elastomer
compound which possesses a reinforcing effect and both electrically
conductive and electrically insulating effects, as well as balanced
strength and elasticity.
DETAILED DESCRIPTION OF THE INVENTION
The inventors of the present invention studied the method for
compounding thermoplastic elastomers, and discovered that
compounding with certain types of ultra fine carbon fibrils gave a
compound with the above mentioned characteristics and well balanced
properties. Hence, the present invention was achieved.
In other words, the present invention offers a crosslinked type
thermoplastic elastomer compound which is obtained by mixing at
least one type of thermoplastic elastomer (100 wt. parts), rubber
like polymer (0-200 wt. parts), and ultra-fine carbon fibrils,
whose diameter is 3.5-70nm and aspect ratio is greater than 5, 1-50
wt. parts against 100 wt. parts of the combined mixture of the
aforementioned elastomer and rubber-like polymer.
The ultra fine carbon fibrils used in the present invention have
practically uniform diameter of 3.5-70 nm, or more preferably 7-25
nm, and length greater about 5 times or more, preferably 50-10,000
times, or most preferably 100-5,000 times the diameter. In
addition, they are practically annular shaped separation-type
carbon fibrils which are characterized by the outer zone composed
of many continuous layers of regularly aligned carbon atoms, and a
separate inner core zone. The aforementioned layered zone and the
core are practically concentric against the cylindrical center line
of the fibrils. It is desirable that the entire fibrils do not
contain any thermal carbon film.
The inner core of the fibrils can be hollow or filled with carbon
atoms with the characteristics of graphite whose alignment is less
regular compared to the regularly aligned carbon atoms in the outer
layer zone.
Desirable carbon fibrils have a 25.5.degree.-26.3.degree.
diffraction angle and 3.38-3.50 angstrom spacing between graphite
layers. A spacing below 3.38 angstroms results in a greater
anisotropic nature, while a spacing greater than 3.50 angstroms
results in poor electrical conductivity.
The ultra-fine carbon fibrils used in the present invention can be
produced by contacting metal containing particles with a carbon
containing gaseous organic compound at a temperature about
850.degree. C.-1200.degree. C. In this case, the dry weight ratio
between the carbon containing organic compound and the metal
containing particles should be at least 100:1.
The metal containing particles and the carbon-containing organic
compound are contacted in the presence of a compound such as
CO.sub.2, H.sub.2, or H.sub.2 O, which forms gaseous products when
it reacts with carbon.
Listed below are examples of the carbon-containing gaseous organic
compound; aromatic hydrocarbons such as benzene, toluene, xylene,
cumene, ethylbenzene, naphthalene, phenanthrene, anthracene, or a
mixture of these compounds; aliphatic hydrocarbons such as methane,
ethane, propane, ethylene, propylene, acetylene, or a mixture of
these compounds; oxyqen containing hydrocarbons such as
formaldehyde, acetoaldehyde, acetone, methanol, ethanol, or a
mixture of these compounds; or carbon monoxide.
Desirable metal-containing particles are iron, cobalt, or
nickel-containing particles whose diameter is in the range of about
3.5-70 nm.
These particles can be carried on a chemically compatible, heat
resistant carrier such as alumina, or silicate which contains
carbon or aluminum silicate.
In a specific example, the surface of metal-containing particles is
independently heated to about 850.degree.-1800.degree. C. by
electromagnetic radiation. The temperature of the metal-containing
particles should be higher than the temperature of the
carbon-containing gaseous compound.
In a particular example, iron-containing particles as
metal-containing particles and benzene as a carbon-containing
organic compound are contacted under pressure at about 1/10-10 atm.
for a period of about 10-180 minutes. The reaction temperature is
900.degree.-1150.degree. C., and the ratio between the carbon
containing organic compound and the iron-containing particles is
greater than about 1,000:1. The contacting can be performed in the
presence of gaseous hydrogen. Further, the iron containing
particles can be carried on a chemically compatible and heat
resistant carrier such as alumina or carbon.
The carbon fibrils produced by the procedures described above have
a practically uniform diameter, and are desirable for attaining the
reinforcing effects and electrical conductivity.
Incidentally, the carbon fibrils produced by the above procedures
tend to form flocks, and it is not advisable to use them as they
are since they have poor dispersion, which is likely to mar the
appearance of a molded product. Therefore, it is desirable to break
the flocks before using them by treating them with a mechanical
breaker such as a vibration mill or ball mill, or by ultrasonic
treatment in the presence of water or solvent, or a combination of
these methods.
In the present invention, the aforementioned ultra-fine carbon
fibrils are compounded in a thermoplastic elastomer in order to
obtain an elastomer compound with various superior
characteristics.
The aforementioned special ultra-fine carbon fibrils have a
relatively large surface area, and thus impart a greater electrical
conductivity as compared to conventionally used electrically
conductive carbon materials. Because of their relatively large
surface area, interaction with the matrix of the resin becomes
greater when the fibrils are combined with a polymer which has high
affinity with the fibrils, resulting in a greater reinforcing
effect as compared to the conventional carbon fiber reinforced
polymer compounds. Further, since a greater resilience can be
obtained as the fiber becomes finer, the possibility of breaking
the reinforcing fiber during the processing is eliminated,
resulting in superior characteristics and high reproducibility of
the molded products.
As it is discussed above, the present invention offers an
ultra-fine carbon fibril compounded elastomer compound having
reinforcing effect and both electrical conductivity and electrical
insulating effects, which could not have been obtained with the
conventional carbon materials.
Listed below are examples of thermoplastic elastomers used in the
present invention: polyolefin type elastomers; styrene-type
elastomers such as styrene-butadiene styrene block co-polymer or
styrene-isoprene-styrene block co-polymer or their hydrogenated
forms; PVC-type elastomers; urethane type elastomers;
polyester-type elastomers; polyamide-type elastomers; polybutadiene
type thermoplastic elastomers such as 1,2 polybutadiene resins or
trans-1,4-polybutadiene; polyethylene-type elastomers such as
methylcarboxylate-polyethylene co-polymers, ethylene vinylacetate
co-polymers, and ethylene-ethylacrylate co polymers; chlorinated
polyethylene; fluorine type thermoplastic elastomer, etc. Among
these materials, 1,2 polybutadiene resins, styrene type elastomers,
and hydrogenated styrene type elastomers are desirable in view of
obtaining a superior reinforcing effect, with 1,2 polybutadiene
being the most desirable.
As the aforementioned 1,2-polybutadiene resins, polymers which
contain more than 30%, or preferably more than 50% of 1,2 vinyl
bondings are desirable in view of their mechanical characteristics.
Their average molecular weights are greater than 1,000, or
preferably greater than 10,000 in view of the green-strength of the
non crosslinked polymer.
In addition, in order to obtain both the desired reinforcing effect
and electrical conductivity, the 1,2-polybutadiene resin ought to
have a suitable degree of crystallization, or specifically 10-70%
crystallization. When the degree of crystallization is below 10%,
the green-strength of the obtained compound becomes low, while the
degree of crystallization above 70% creates processing problems due
to the high temperature required for processing 1,2-polybutadiene
resin.
In the compounds covered by the present invention, the
1,2-polybutadiene resin can be used by itself; or more than two
kinds of 1,2-polybutadiene resins with different 1,2 structures or
different degrees of crystallization may be combined; or the resins
may be blended with other rubber-like polymers.
Further, the compounds covered by the present invention can be
obtained by blending rubber-like cis-1,4-polybutadiene,
styrene-butadiene co-polymer rubber, ethylene-propylene,
di-functional monomer rubber ("EPDM") chloroprene rubber, butyl
rubber, halogenated butyl rubber, acrylonitrile-butadiene
co-polymer rubber, acrylic rubber, etc. ("non-thermoplastic
elastomer rubbers") with the aforementioned thermoplastic
elastomers depending on the application.
The blending ratio of these non-thermoplastic elastomer rubbers
against the thermoplastic elastomer should be less than 200 wt.
parts per 100 wt. parts of the thermoplastic elastomer. When more
than 200 wt. parts of non-thermoplastic elastomer material is
blended, the reinforcing effect associated with the superior
affinity between the ultra-fine carbon fibrils and the
thermoplastic elastomer cannot be maintained.
The aforementioned thermoplastic elastomer or its blended mixture
with a rubber-like material can be cured in the crosslinking
processes commonly used in the rubber industry, by adding sulfur
for vulcanization, vulcanization accelerator, vulcanization aid and
thermosetting resin such as phenol resin for thermosetting resins,
hardening catalyst such as Lewis acid, peroxide for crosslinking
peroxide compounds, and co-crosslinking agent (multi-functional
methacrylate, divinyl benzene, dimaleimide, etc.).
Some examples of the aforementioned vulcanization accelerators
include ammonium aldehydes, aminoaldehydes, guanidines, thioureas,
thiazols, dithiocarbamates, xanthogenes, thiurams, etc. Examples of
vulcanization aids include stearic acid, oleic acid, lauric acid,
zinc white, litharge, magnesium oxide, zinc-stearate, etc.
The effects intended in the present invention can be obtained by
compounding 1-50 wt. parts, or more preferably 2-30 wt. parts, or
most preferably 3-20 wt. parts of the ultra-fine carbon fibrils
used in the present invention against 100 wt. parts of the combined
mixture of the aforementioned thermoplastic elastomer and the
aforementioned non-thermoplastic elastomer. The reinforcing effects
are not sufficient when the amount of ultra-fine carbon fibrils is
below 1 wt. part, while the amount should not exceed 50 wt. parts
so that the superior processing characteristic of the elastomer
specific to 1,2-polybutadiene may not be lost.
The compounds covered by the present invention are prepared by
using known mixing and processing devices such as a kneader,
Bambary mixer, plastomill, or rolls.
Further, desired shapes can be formed by using any known method
such as extrusion molding, press molding, etc.
Aside from the ultra-fine carbon fibrils, particle type reinforcing
materials such as carbon black or silica fillers, or inorganic and
organic reinforcing fibers such as glass fiber, aramid fiber, or
carbon fiber can be blended in the compounds covered by the present
invention. Antioxidants, stabilizers, processing aids, and flame
retardants may also be blended.
The thermoplastic elastomers compounded with ultra-fine carbon
fibrils covered by the present invention possess unique
characteristics which cannot be attained by other resins and rubber
like materials, as well as superior reinforcing effects and
electrical conductivity compared to compounds with carbon fibers
conventionally used for imparting electrical conductivity. The
compounds covered by the present invention are elastomers which
result in less noise due to static generation, and feature superior
mechanical characteristics. Therefore, they are suitable as a
material for electrical parts, electronic parts, housing for OA
machineries, structural materials, electrically conductive floors,
electrically insulating shoes, semiconductive layers of power
cables, etc.
EXAMPLES
The present invention will be explained in further detail by
application examples.
Application Examples 1-3
Ultra fine carbon fibrils (diameter: 30nm, length: 30 microns,
phase interval measured by wide angle X-ray diffraction: 3.45
angstroms, diffraction angle:26.8.degree. ) were mixed with a 1,2
polybutadiene type thermoplastic elastomer (Nippon Synthetic Rubber
Co., RB 810) at 100/5, 100/10, and 100/15 mixing ratios by using a
kneader at 140.degree. C. for a period of 10 minutes. After the
kneading, sheets were formed by and pressed to 2 mm thick by a
press mold (140.degree. C..times.5 min.). A set of rolls, Dumbell
type (JIS #3) test pieces were then punched out in the direction of
roll alignment as well as in the perpendicular direction.
Tensile stress at 100% elongation (M.sub.100) and at 300%
elongation (E.sub.b) tensile strength (T.sub.b), and breaking
elongation (E.sub.b) of the obtained test pieces were measured by a
tensile strength tester. JIS A hardness, Vicat softening
temperature, and volumetric resistivity were also measured.
Further, appearance of the molded parts was visually observed in
order to evaluate the surface conditions. Product parts with
superior surface gloss and a smooth surface without any exposed
carbon material were classified as 0, while product parts with poor
surface gloss or with an irregular surface with exposed carbon
material were classified as X.
Results are shown in Table 1.
Reference Example 1
The 1,2-polybutadiene used in Application Example 1 was press
molded alone, and test pieces were prepared in the same manner as
in Application Examples 1-3. Results obtained by the similar tests
are shown in Table 1.
Reference Examples 2-4
Test pieces were prepared in the same manner as Application
Examples 1-3 using electrically conductive carbon black (Lion Akuzo
KK, Kichen Black EC-DJ 500) in place of the ultra-fine carbon
fibrils used in Application Examples 1-3, and similar tests were
conducted. Results are shown in Table 1.
Reference Examples 5-7
Test pieces were prepared in the same manner as Application
Examples 1-3 using reinforcing carbon black (HAF CB) (Mitsubishi
Kasei K.K., Diablack) in place of the ultra fine carbon fibrils
used in Application Examples 1-3, and similar tests were conducted.
Results are shown in Table 1.
Reference Examples 8-10
Test pieces were prepared in the same manner as Application
Examples 1-3 using carbon fiber chopped into 10 mm length (Toray
Industries, HTA W1000) in place of the ultra-fine carbon fibrils
used in Application Examples 1-3, and similar tests were conducted.
Results are shown in Table 1.
In all examples, stress strain analyses were conducted not only in
the roll alignment direction but also in the perpendicular
direction for the systems in which 15 wt. parts of carbon
reinforcing material or electrical conductivity imparting additive
(called reinforcing filler hereinafter) against 100 wt. parts of
1,2-polybutadiene was blended, in order to study anisotropic
characteristics of the products.
As to the effects of compounding ultra-fine carbon fibrils in
1,2-polybutadiene in the compounds covered by the present
invention, increases in M.sub.100, M.sub.300 and T.sub.b, which
represented the strength characteristics, were significant compared
to other systems.
With regard to the volumetric resistivity, the compound system with
carbon fibers showed the smallest resistivity. However, this system
had poor product appearance and showed anisotropic strength
characteristics. In other words, it was confirmed that the
compounds covered by the present invention showed well balanced
characteristics and high performance in strength characteristics
such as tensile stress and tensile strength, and electrically
conductive characteristics.
Application Examples 4-6
Zinc-white (3 wt. parts), stearic acid (1 wt. part),
dibenzothiazil-disulfide, as a vulcanization accelerator (1.5 wt.
parts), and tetramethyl-thiuramdisulfide (0.55 wt. parts) were
added against 100 wt. parts of 1,2-polybutadiene to the compounds
obtained in Application Examples 1-3, and they were processed in
the same manner as Application Examples 1-3. The obtained products
were press-vulcanized at 160.degree. C. for a period of 20 minutes.
Incidentally, these conditions were confirmed to be the optimum
vulcanization conditions based on the measurement by the JSR
Curastometer (Nippon Synthetic Rubber Co.) vulcanization
tester.
The test pieces for the tensile test were punched out in the
direction of roll alignment used for the sheet formation as in
Application Examples 1-3. Incidentally, the tensile test was
conducted in the direction perpendicular to the roll alignment in
the case of compound systems with 15 wt. parts of a filler
reinforcement. The tests included M.sub.100, M.sub.300, T.sub.b,
and E.sub.b by a tensile tester, hardness by the JIA A method,
measurement of volumetric resistivity, and visual evaluation of
appearance. Results are shown in Table 2.
Reference Example 11
Following the same procedure used in Application Example 4, a
vulcanized compound was produced from a 1,2 polybutadiene single
system used in Reference Example 1. Results are shown in Table
2.
Reference Examples 12-14
These are examples of vulcanized systems which correspond to
Reference Examples 5-7, produced by Kichen black following the same
procedure used in Application Examples 4-6. Results are shown in
Table 2.
Reference Examples 15-17
These are examples of vulcanized systems which correspond to
Reference Examples 5-7, produced by HAF carbon-black following the
same procedure used in Application Examples 4-6. Results are shown
in Table 2.
The vulcanized compounds obtained by Application Examples 4-6 had
an excellent appearance as well as excellent reinforcing effects
and electrically conductivity imparting effect, confirming the
superiority of the compounds produced by the present invention.
Application Examples 7-9
Sheets where prepared following the procedures used in Application
Example 3, but using styrene-butadiene-styrene block co-polymer
(SBS) (Nippon Synthentic Rubber, Co., TR-1000, contains 50 phr
extension oil), styrene-(ethylene-butylene)-styrene block
co-polymer (SEBS) (Shell Ltd., Krayton G1650),
ethylene-methacrylate co polymer (EMA) (Mitsui Dupont Chemical,
Co., Nucler 599) were respectively used in place of
1,2-polybutadiene used in Application Example 3. Test results are
shown in Table 3.
Reference Examples 18-20
Sheets were prepared following the procedures used in Application
Examples 7-9, but using reinforcing type carbon black (HAH CB) in
place of the ultra-fine carbon fibrils used in Application Examples
7-9, and tested. Results are shown in Table 3.
Reference Example 21
Test pieces were prepared following the procedures used in
Application Example 3, but using cis-1,4-polybutadiene (BR) (Nippon
Synthetic Rubber, JSR BR01) in place of 1,2-polybutadiene used in
Application Example 3. Ultra fine carbon fibrils were added, then
the following were mixed; 3 wt. parts of zinc-white as
vulcanization accelerator aid, 5 wt. parts of propyl oil, 2 wt.
parts of stearic acid, 0.8 wt. parts each of
N-phenyl-N'-isopropyl-p-phenylenediamine as anti-aging agent,
N-cyclohexyl-2-benzothiazilsulfamide as vulcanization accelerator,
and 1.75 wt. parts of sulfur against 100 wt. parts of
polybutadiene. The mixture was press-vulcanized at 45.degree. C.
for a period of 30 minutes. The results are shown in Table 3.
Reference Example 22
Test pieces were prepared in the same manner as Reference Example
21, with filling reinforcing type carbon black (HAF CB) used in
place of the ultra-fine carbon fibrils used in Reference Example 21
and similar tests were conducted. The results are shown in Table 3.
26.
Other embodiments are within the following claims.
TABLE 1
__________________________________________________________________________
Applicat. Applicat. Applicat. Reference Reference Reference
Reference Example 1 Example 2 Example 3 Example 1 Example 2 Example
3 Example
__________________________________________________________________________
4 Type & Qty. Ultra-fine Ultra-fine Ultra-fine EC-DJ500
EC-DJ500 EC-DJ500 EC-DJ500 of reinforc- carbon carbon carbon 0 5 10
15 ing filler fibrils fibrils fibrils (phr) 5 10 15 Roll Perpen-
Roll Perpen- alignment dicular alignment dicular direction
direction direction direction 100% Tensile 55 82 106 88 33 39 47 55
53 Stress M.sub.100 (kg/cm.sup.2) 300% Tensile 72 96 -- -- 42 51 61
68 66 Stress M.sub.300 (kg/cm.sup.2) Tensile 72 96 121 108 69 66 66
69 67 Strength T.sub.b (kg/cm.sup.2) Breaking 440 300 250 300 820
760 570 450 470 Elongation E.sup.b (%) Vicat Soft- 42 43 45 45 44
45 46 ening Temp. (.degree.C.) Volumetric 2.2 .times. 10.sup.9 5.4
.times. 10.sup.5 7.3 .times. 10.sup.4 2.0 .times. 10.sup.17 1.8
.times. 10.sup.12 1.2 .times. 10.sup.9 3.5 .times. 10.sup.7
Resistivity (Ohm. cm) Hardness 88 90 92 79 82 83 87 (JIS A)
Appearance 0 0 0 0 0 0 0
__________________________________________________________________________
Reference Reference Reference Reference Reference Reference Example
5 Example 6 Example 7 Example 8 Example 9 Example
__________________________________________________________________________
10 Type & Qty. HAF CB HAF CB HAF CB HTA W1000 HTA W1000 HTA
W1000 of reinforc- 5 10 15 5 10 15 ing filler (phr) Roll Perpen-
Roll Perpen- alignment dicular alignment dicular direction
direction direction direction 100% Tensile 36 38 41 39 42 47 -- 35
Stress M.sub.100 (kg/cm.sup.2) 300% Tensile 46 51 59 56 45 48 -- 40
Stress M.sub.300 (kg/cm.sup.2) Tensile 73 71 73 67 63 59 79 53
Strength T.sub.b (kg/cm.sup.2) Breaking 830 710 710 63 690 550 70
600 Elongation E.sup.b (%) Vicat Soft- 38 38 39 43 42 42 ening
Temp. (.degree.C.) Volumetric 7.8 .times. 10.sup.16 7.0 .times.
10.sup.16 6.2 .times. 10.sup.16 7.5 .times. 10.sup.7 3 .times.
10.sup.4 3.5 .times. 10.sup.2 Resistivity (Ohm. cm) Hardness 85 86
86 85 86 88 (JIS A) Appearance 0 0 0 0 X X
__________________________________________________________________________
TABLE 2
__________________________________________________________________________
Applicat. Applicat. Applicat. Reference Reference Reference Example
4 Example 5 Example 6 Example 11 Example 12 Example 13
__________________________________________________________________________
Type & Qty. Ultra-fine Ultra-fine Ultra-fine 0 EC-DJ500
EC-DJ500 of reinforc- carbon carbon carbon 5 10 ing filler fibrils
fibrils fibrils (phr) 5 10 15 Roll Perpen- alignment dicular
direction direction 100% Tensile 65 102 145 102 30 42 52 Stress
M.sub.100 (kg/cm.sup.2) 300% Tensile -- -- -- -- 59 90 108 Stress
M.sub.300 (kg/cm.sup.2) Tensile 115 158 195 172 83 114 151 Strength
T.sub.b (kg/cm.sup.2) Breaking 290 230 180 210 370 360 400
Elongation E.sup.b (%) Volumetric 1.8 .times. 10.sup.4 3.0 .times.
10.sup.3 90 2.3 .times. 10.sup.16 1.8 .times. 10.sup.7 1.1 .times.
10.sup.3 Resistivity (Ohm. cm) Hardness 80 85 90 74 80 84 (JIS A)
Appearance 0 0 0 0 0 0
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Reference Reference Reference Reference Example 14 Example 15
Example 16 Example 17
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Type & Qty. EC-DJ500 HAF CB HAF CB HAF CB of reinforc- 15 5 10
15 ing filler (phr) Roll Perpen- Roll Perpen- alignment dicular
alignment dicular direction direction direction direction 100%
Tensile 60 59 38 40 47 47 Stress M.sub.100 (kg/cm.sup.2) 300%
Tensile 128 125 86 106 -- 132 Stress M.sub.300 (kg/cm.sup.2)
Tensile 160 145 97 111 125 132 Strength T.sub.b (kg/cm.sup.2)
Breaking 390 400 320 310 290 300 Elongation E.sup.b (%) Volumetric
25 9.7 .times. 10.sup.15 8.2 .times. 10.sup.15 8.0 .times.
10.sup.15 Resistivity (Ohm. cm) Hardness 87 79 80 83 (JIS A)
Appearance 0 0 0 0
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TABLE 3
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Applicat. Applicat. Applicat. Reference Reference Reference
Reference Reference Example 7 Example 8 Example 9 Example 18
Example 19 Example 20 Example Example
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22 Polymer Mater. SBS SEBS EHA SBS SEBS EHA BR BR Type & Qty.
Ultra-fine Ultra-fine Ultra-fine HAF CB HAF CB HAF CB Ultra-fine
HAF CB of reinforc- carbon carbon carbon 15 15 15 carbon 15 ing
filler fibrils fibrils fibrils fibrils (phr) 5 10 15 15 100%
Tensile 57 104 95 24 27 76 44 10 Stress M.sub.100 (kg/cm.sup.2)
300% Tensile 85 208 145 42 178 95 82 15 Stress M.sub.300
(kg/cm.sup.2) Tensile 236 281 180 185 242 134 134 38 Strength
T.sub.b (kg/cm.sup.2) Breaking 560 350 360 750 400 450 450 590
Elongation E.sup.b (%) Volumetric 75 50 20 4.6 .times. 10.sup.15
6.7 .times. 10.sup.15 1.4 .times. 10.sup.11 85 7.2 .times.
10.sup.14 Resistivity (Ohm. cm) Hardness 84 (Shoa D) (Shoa D) 72
(Shoa D) (Shoa D) 60 44 (JIS A) 59 90 45 65 Appearance 0 0 0 0 0 0
0 0
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